The invention relates to a method for evaluating the applied welding current intensity during electrical resistance seam welding of overlap seams of consecutive container bodies of a production series. Furthermore, the invention relates to a welding device for the resistance seam welding of container bodies, comprising welding rollers, a welding current generator and a welding current controller, as well as an installation for the multiple detection along the welding seam of a container body of the electrical energy brought into the welding seam and/or for the multiple detection of the temperature of the welding seam of a container body along the welding seam.
Furthermore, the invention is related to a method and a welding device for welding container body seam welds with non-uniform overlapping of the edges of the container body material.